Validation of Decisional Balance and Self-Efficacy Measures for HPV Vaccination in College Women

Purpose. Women younger than 25 years are at greatest risk for human papillomavirus (HPV) infection, including high-risk strains associated with 70% of cervical cancers. Effective model-based measures that can lead to intervention development to increase HPV vaccination rates are necessary. This study validated Transtheoretical Model measures of Decisional Balance and Self-Efficacy for seeking the HPV vaccine in a sample of female college students. Design. Cross-sectional measurement development. Setting. Online survey of undergraduate college students. Subjects. A total of 340 female students ages 18 to 26 years. Measures. Stage of Change, Decisional Balance, and Self-Efficacy. Analysis. The sample was randomly split into halves for exploratory principal components analyses (PCAs), followed by confirmatory factor analyses (CFAs) to test measurement models. Multivariate analyses examined relationships between constructs. Results. For Decisional Balance, PCA indicated two 4-item factors (Pros -alpha = .90; and Cons -alpha = .66). CFA supported a two-factor correlated model, chi(2) (19) = 39.33; p < .01; comparative fit index (CFI) = .97; and average absolute standardized residual statistic (AASR) = .03; with Pros alpha = .90 and Cons alpha = .67. For Self-Efficacy, PCA indicated one 6-item factor (alpha = .84). CFA supported this structure, chi(2) (9) = 50.87; p < .05; CFI = .94; AASR = .03; and alpha = .90. Multivariate analyses indicated significant cross-stage differences on Pros, Cons, and Self-Efficacy in expected directions. Conclusion. Findings support the internal and external validity of these measures and their use in Transtheoretical Model-tailored interventions. Stage-construct relationships suggest that reducing the Cons of vaccination may be more important for HPV than for behaviors with a true Maintenance stage.